Tricuspid regurgitation (TR) is a common form of heart valve disease where the valve between the heart’s two right-sided chambers does not close properly. This malfunction causes blood to leak backward, or regurgitate, into the upper chamber with each heartbeat. The condition forces the heart to work harder to move blood through the circulatory system. While mild TR is often considered a normal finding that may not require intervention, the moderate form is significant enough to warrant careful attention and monitoring.
The Tricuspid Valve and Regurgitation Explained
The heart contains four valves, and the tricuspid valve is positioned between the right atrium, which receives deoxygenated blood from the body, and the right ventricle, which pumps that blood to the lungs. This valve is composed of three flaps of tissue, or leaflets, whose coordinated opening and closing ensure one-way blood flow. When the right ventricle contracts during systole to push blood toward the lungs, the tricuspid valve leaflets should seal tightly.
Regurgitation occurs when the leaflets fail to coapt, or meet fully, during this contraction phase. The incomplete closure allows a portion of the blood to flow backward into the right atrium. This backward flow increases the volume and pressure in the right atrium and the venous system, as blood starts to back up. Over time, this inefficiency can cause the right-sided chambers of the heart to enlarge and function less effectively.
What Defines Moderate Severity
Tricuspid regurgitation is categorized into different grades: trace, mild, moderate, or severe, based on the quantity of blood leaking backward. This grading system determines the condition’s impact and the need for intervention. A moderate classification indicates that the backflow of blood is greater than mild but less extensive than severe regurgitation.
Grading is primarily determined through a transthoracic echocardiogram, which uses ultrasound to visualize the heart’s structure and blood flow. Key measurements used to define moderate severity include the width of the regurgitant jet, known as the vena contracta, and the volume of blood leaking backward per beat. Moderate TR suggests a measurable strain on the right side of the heart.
Primary Causes and Associated Symptoms
The most frequent reason for tricuspid regurgitation is not an issue with the valve itself but a secondary problem caused by enlargement of the right ventricle. This is known as functional or secondary TR, and it often results from increased pressure within the heart or lungs. Conditions like pulmonary hypertension, which is high blood pressure in the arteries of the lungs, or left-sided heart failure can cause the right ventricle to expand. The expansion pulls the valve leaflets apart, preventing them from closing completely.
Less commonly, the regurgitation is primary, meaning it is caused by direct damage to the valve structure, such as from an infection, congenital defect, or a pacemaker lead. Regardless of the cause, moderate tricuspid regurgitation can lead to symptoms that result from blood backing up in the veins that return blood to the heart. Patients may experience swelling, or edema, in the abdomen, legs, or ankles due to fluid retention.
Other common symptoms include fatigue and shortness of breath, particularly during physical activity, because the heart is unable to efficiently move oxygen-poor blood to the lungs. A noticeable throbbing or pulsing sensation in the neck veins can also occur due to the increased pressure in the right atrium. These symptoms often indicate the heart is struggling to maintain proper blood flow and volume control.
Management and Monitoring Strategies
Management for moderate tricuspid regurgitation often begins with addressing the symptoms and treating the underlying cause, if one is identified. A primary medical strategy involves the use of diuretics, which are commonly called water pills, to help manage fluid retention and relieve the associated symptoms of swelling. Reducing dietary salt intake is also an important lifestyle modification that supports fluid management.
Because moderate TR can progress, regular monitoring is a central part of the management plan. This typically involves serial echocardiograms to track the severity of the regurgitation and assess the size and function of the right ventricle. If moderate TR is discovered in a patient who requires surgery for a problem with a left-sided heart valve, repair of the tricuspid valve may be considered at the same time. Surgical or transcatheter intervention is usually reserved for cases that become severe or when symptoms significantly worsen despite medical therapy.